Electrical connector and method of making same

ABSTRACT

AN ELECTRICAL CONNECTOR INCLUDES A BODY MEANS HAVING MEANS FOR SECURING AN ELECTRICAL MEMBER THERETO. THE BODY MEANS IS FORMED TO A ZINC BASE ALLOY COMPRISING ALUMINUM, COPPER, CADMIUM, TIN, LEAD, MAGNESIUM, IRON AND ZINC WITHIN CERTAIN CRITICAL RANGES. THE ZINC ALLOY IS HEATED TO A MOLTEN STATE AND THE MOLTEN ALLOY IS THEN PRESSURE OR GRAVITY MOLDED, SUBJECTED TO FAST CHILLING AND CHEMICALLY TREATED TO FORM AN ELECTRICAL CONNECTOR FREE FROM CORROSION.

ELECTRICAL CONNECTOR AND METHOD OF MAKING SAME C. B. HAEGERT OriginalFiled Feb. 27, 1970 United States Patent 3,748,189 ELECTRICAL CONNECTORAND METHOD OF MAKING SAME Clarence B. Haegert, 1211 Elm St.,Coifeyville, Kans.

Application Feb. 27, 1970, Ser. No. 15,267, now Patent No. 3,656,094,which is a continuation-in-part of application Ser. No. 610,878, Jan.23, 1967. Divided and this application Jan. 31, 1972, Ser. No. 222,222

Int. Cl. B22d 25/02, 17/00 U.S. Cl. 148-3 3 Claims ABSTRACT OF THEDISCLOSURE An electrical connector includes a body means having meansfor securing an electrical member thereto. The body means is formed of azinc base alloy comprising aluminum, copper, cadmium, tin, lead,magnesium, iron and zinc within certain critical ranges. The zinc alloyis heated to a molten state and the molten alloy is then pressure orgravity molded, subjected to fast chilling and chemically treated toform an electrical connector free from corrosion.

This is a division of application Ser. No. 15,267, filed Feb. 27, 1970,now U.S. Pat. 3,656,094, which is a continuation-in-part of Ser. No.610,878, filed J an. 23, 1967.

BACKGROUND OF THE INVENTION The present invention relates to electricalconnectors of various types and to the method of making them. Electricalconnectors of this type including means for securing an electricalmember thereto have in the past been generally formed of a brass-leadalloy or a copper alloy. Such prior art connectors are relativelyexpensive and are subject to excessive corrosion, particularly in anenvironment containing sulphuric acid. This excessive cost arises due tothe materials employed in the connectors as well as the method ofcasting the connectors. Zinc base alloys, which exhibit superiorelectrical and tensile properties have not been successfully applied inenvironments containing sulphuric acid due to the highly corrosiveeffect of sulphuric acid on zinc.

SUMMARY OF THE INVENTION The present invention relates to an electricalconnector and the method of making the electrical connector wherein thebody means thereof is formed of a zinc base alloy manufactured in aparticular manner. This utilization of the zinc base alloy of thepresent invention substantially reduces the cost of the connector sincethe materials involved are cheaper, and furthermore, the connector canbe readily manufactured by sand casting or die casting.

Also, surprisingly enough, it has been found that electrical connectorsmade of such a zinc base alloy according to the present invention havebetter electrical conductivity than prior art connectors made of a brasslead alloy or a copper alloy, and also exhibit good tensile strength.Additionally, the connector of the present invention has very goodresistance to corrosion even when it comes in contact with sulphuricacid, which is normally highly corrosive to zinc and zinc base alloys.

An object of the present invention is to provide a new and novelelectrical connector having good electrical conductivity, good tensilestrength, and further which is resistant to corrosion.

A further object of the present invention is to provide a uniqueelectrical connector made of a zinc base alloy which is resistant tocorrosion by sulphuric acid.

3,748,189 Patented July 24, 1973 BRIEF DESCRIPTION OF THE DMWING FIG. 1is a top perspective view illustrating a first form of electricalconnector or battery terminal according to the present invention;

FIG. 2 is a top perspective view illustrating a second form ofelectrical connector or battery terminal according to the presentinvention;

FIG. 3 is a top perspective view of a further electrical connectoraccording to the present invention;

FIG. 4 is a top perspective view of still another electrical connectoraccording to the present invention; and

FIG. 5 is a top perspective exploded view of the structure illustratedin FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawingswherein like reference characters designate corresponding partsthroughout the several views, a first form of electrical connector isillustrated in FIG. 1 wherein the connector is indicated generally byreference numeral 12 and comprises a battery terminal.

This connector or battery terminal includes a body means 14 having anintegral hollow cylindrical portion 16 for receiving an electrical cableor the like. The body means is also bifurcated at one end to form a pairof spaced integral leg portions 18 and 20 having a tapered bore 24defined therebetween for receiving the post of a battery whereby thedevice is adapted to operate as a conventional battery terminalconnector.

A bolt 30 extends through aligned holes provided in the outer ends oflegs 18 and 20, the bolt 30 having an enlarged head portion 32 receivedwithin a cutout 34 provided in the outer surface of leg portion 20 ofthe body means. A nut 36 is threaded on the far end of the bolt as seenin FIG. 1 for clamping the connector on a battery post.

A small screw 40 is adapted to be threaded into a tapped hole providedin enlarge head 32 for securing a lug 42 to the battery terminal. Thislug has a suitable hole provided therein for receiving the threadedshank portion of screw 40. The end portion 44 of lug 42' is hollow forreceiving a suitable electrical member which is crimped thereto.

A threaded stud 50 extends upwardly from portion 16 of the batteryterminal and has a tapped hole formed therein for receiving a smallscrew 52 which is employed for holding lug 54 in place, lug 54 being ofsubstantially the same construction as lug 42.

Referring now to FIG. 2 of the drawing, a modified electrical connectoror batter terminal is indicated generally by reference numeral 60. Thisbattery terminal includes a body means 62 having a hollow cylindricalportion 64 for receiving an electrical cable or the like. The body meansalso includes a pair of spaced leg portions 66 and 68 having alignedholes 70 and 72 formed therethrough for receiving a suitable nut andbolt assembly for clamping the battery terminal on a battery post.

A tapered bore 74 is formed between spaced legs 66 and 68 for receivinga conventional battery post.

Referring now to FIG. 3, a further modified form of electrical connectoraccording to the present invention is illustrated. The electricalconnector is indicated generally by reference numeral and includes abody means including a flat end portion 82 having a hole 84 formedtherethrough. The opposite end portion 86 of the body means is ofgenerally cylindrical configuration and is hollow for receiving a cableor the like, the bared end of the cable being crimped in position withinsuch hollow end portion of the body means.

3 Referring now to FIGS. 4 and 5, a still further modified form ofelectrical connector is illustrated. The connector is indicatedgenerally by reference numeral 90 and includes a three-part body means,the body means including a bolt 92 having an enlarged hex head 94 at oneend thereof and having a longitudinally extending slot 96 formedtherein. The external portion of the lower part of the bolt is providedwith threads 98.

The body means includes an intermediate member 100 the main portion ofwhich is adapted to slide within the slot 96 formed in bolt 92. Member100 includes depending leg portions 102 and 104 which are spaced apartand which are adapted to be inserted through a threaded bore 106provided in a nut 108 and then turned upwardly as indicated in phantomlines in FIG. 5 so as to retain members 100 and 108 in assembledrelationship as seen in FIG. 4. The threaded bore 106 is adapted to bethreaded on the external threads 98 provided on the bolt 92.

As seen most clearly in FIG. 5, the upper surface of member 100 isprovided with a central generally V-shaped groove or notch 110'. A pairof lugs 112 extend outwardly in opposite directions from one end ofmember 100, and a similar pair of lugs 114 extend outwardly in oppositedirections from the opposite end of member 100. The portion of member100 between lugs 112 and 114 is adapted to fit within the slot 96provided in bolt member 92, lugs 112 and 114 serving to retain member100 in position and to guide its movement in a vertical direction asseen in the drawings.

It is apparent that when the electrical connector is in the assembledrelationship shown in FIG. 4, rotation of nut 108 with respect to bolt92 will cause member 100 to be raised and lowered within the slot 96 inthe bolt member whereby a suitable electrical member may be clampedbetween the notch 110 in the upper surface of member 100 and theundersurface of the hex head 94 of the bolt.

The body means of each of the electrical connectors as described inconnection with FIGS. 1 through 5 inclusive is formed of a zinc basealloy having a particular composition.

The following three examples represent compositions suitable for use asthe body means of an electrical connector according to the presentinvention:

Example I Aluminum 3.9 to 4.3%. Copper .75 to 1.25%. Magnesium .03 to.06%. Iron Up to .075% maximum. Lead Up to .003% maximum. Cadmium Do.Tin Up to .002% maximum. Zinc Balance.

Example II Aluminum 3.5 to 4.5%. Copper 2.5 to 3.5%. Magnesium .02 to.l0%. Iron Up to 100% maximum. Lead Up to 007% maximum. Cadmium Up to.005% maximum. Tin Do. Zinc Balance.

Example 111 Aluminum 3.9 to 4.3%. Copper Up to maximum. Magnesium .03 to0.6%. Iron Up to .075% maximum. Lead Up to .003% maximum. Cadmium o. TinUp to .002% maximum. Zinc Balance.

In each of the above examples, the percentages are by weight of thecomposition, and it will be noted that in each case the major portion ofthe composition comprises zinc which is the balance of the compositionin each of the three examples.

In the present invention, the method of making the electrical connectorincludes the steps of heating one of the aforedescribed alloys to amolten state at a particular temperature, pressure or gravity moldingthe molten alloy at a particular pressure and for a specific time toform an electrical connector, subjecting the molded or injectedconnector to fast chilling to keep the grain structure of the connectorvery fine, and then chemically treating the connector in a suitablechemical bath to seal the pores of the connector against penetration andintergranular corrosion by sulphuric acid.

Specifically, the method of making the electrical connector includes thesteps of heating one of the aforedescribed alloys to a molten state atabout 765 degrees Fahrenheit. A steel cavity mold is heated at about 450degrees Fahrenheit and maintained within close limits at thistemperature by means of circulating cooling water or the like around thecavity mold. The temperature of the molten alloy within the mold shouldnot vary more than about :4 degrees Fahrenheit because the hardness andtensile strength of the metal increase at lower temperatures anddecrease at higher temperatures.

The molten alloy is injected into the mold and subjected to tons ofpressure for about 1.4 seconds while in the mold and is then kept in themold for a dwell time of about another 2.8 seconds with this pressurereleased and while maintaining the temperature of the mold at about 450degrees Fahrenhiet, allowing the metal to solidify. This procedureincreases the density of the metal and insures proper porosity of themetal.

The heat from the molten alloy is transferred to the mold and hence tothe circulating cooling Water and the pressures and temperatures towhich the metal is subjected give the metal impact resistance andelongation.

The solidified metal is quenched immediately after its removal from themold, which increases the mechanical properties of the metal at least7500 pounds per square inch higher than if allowed to cool in air.

After the quenching operation, the metal is subjected to a chemicaltreatment in a bath of trichloroethylenecarbon tetrachloride to seal thesurface of the metal against penetration and intergrannular corrosion by$111- phuric acid and the like.

The cycle of injecting the molten metal into the mold, subjecting themetal to the pressure at the times stated and removing the metal fromthe mold is controlled by a series of automatic timers. The mold cavityis thus automatically prepared for another injection of molten metalinto the cavity under 2000 pounds of exerted pressure.

It is apparent from the foregoing that there is provided a new and novelelectrical connector body means having means for securing an electricalconnector member thereto and wherein the body means is formed of a zincbase alloy which enables the connector to be manufactured at a lowercost with good electrical conductivity, good tensile strength, and goodcorrosion resistance characteristics.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, and since thescope of the invention is defined by the appended claims, all changesthat fall within the metes and bounds of the claims or that form theirfunctional as well as conjointly cooperative equivalents are thereforeintended to be embraced by those claims.

.10% magnesium, up to about .10% iron, up to about 5 .007% lead, up toabout .005% cadmium, up to about .005% tin, up to about 3.5% copper, thebalance being zinc, all of said percentages being by weight of thecomposition, heating said alloy to a molten state, subjecting said alloyto about 100 tons of pressure for about 1.4 10

seconds, releasing the 100 tons of pressure and keeping the alloy in themold for a dwell time of about 2.8 seconds to allow the alloy tosolidify to form an electrical connector, subjecting the said pressuremolded connector to fast quenching to make the grain structure of theconnector fine, and chemically treating the connector in a bath oftrichloroethylene-carbon tetrachloride after the quenching operation toseal the pores of the connector against penetration and intergranularcorrosion by sulphuric acid.

2. The method as defined in claim 1, wherein the alloy is heated toabout 765 degrees Fahrenheit in its molten state.

3. The method as defined in claim 1, wherein the mold 6 References CitedUNITED STATES PATENTS 291,286 1/1884 Brewer 339278 C X 1,467,651 9/1923Prax 339-224 2,095,825 10/1937 McRae 339278 C X 3,175,181 3/1965 Grabbe339278 C 3,493,034 2/1970 Haegert 164-113 X FOREIGN PATENTS 650,2119/1928 France 136134 144,280 11/1951 Australia 136-135 R 736,907 9/1955Great Britain 136135 R OTHER REFERENCES Handbook of EngineeringMaterials, Miner et a1. (1955), John Wiley & Sons Inc., New York, pp.2-353- 2-361.

Materials and Methods, Cast Zinc Alloys, No. 199, October 1950, p. 91.

Zamak Alloys for Zine Alloy Die Castings, New Jersey Zinc Co., New York(1944) CHARLES N. LOVELL, Primary Examiner US. Cl. X.R.

is kept at a temperature of about 450 degrees Fahrenheit. 25 134-41;164-113, 120, 122, 128

